Multiple Sclerosis Optic Neuritis Research Articles

Early Orbital Blood Flow Changes in Multiple Sclerosis Patients with Unilateral Acute Optic Neuritis

The aim of this study was to evaluate orbital blood flow by using colour Doppler imaging before corticosteroid administration in multiple sclerosis patients with unilateral acute optic neuritis. Thirty multiple sclerosis patients with unilateral acute optic neuritis and 30 healthy subjects were included as the study and the control groups. The diagnosis of multiple sclerosis optic neuritis was based on clinical presentation, visually evoked potential, and magnetic resonance imaging findings. Data obtained from affected and unaffected eyes were compared with each other and the control group. Ophthalmic artery peak systolic velocity, end-diastolic velocity, resistivity index, and pulsatile index were measured in all patients before administration of systemic corticosteroid treatment and in control subjects. All parameters of blood flow obtained from affected eyes of patients who developed acute optic neuritis were significantly higher than those of the clinically uninvolved eyes of the affected patients (p < 0.001) and those of control eyes (p < 0.001). In addition, statistically significant increases were found in ophthalmic artery peak systolic velocity, end-diastolic velocity, and resistivity index of the clinically uninvolved eye of the affected patients compared with the control group (p = 0.002, p = 0.012, p = 0.013, respectively). No significant differences were found in blood flow data between left and right eyes of the control group (p > 0.05).

Ganglion Cell Loss in Relation to Visual Disability in Multiple Sclerosis

We used high-resolution spectral-domain optical coherence tomography (SD-OCT) with retinal segmentation to determine how ganglion cell loss relates to history of acute optic neuritis (ON), retinal nerve fiber layer (RNFL) thinning, visual function, and vision-related quality of life (QOL) in multiple sclerosis (MS). Cross-sectional study. A convenience sample of patients with MS (n = 122; 239 eyes) and disease-free controls (n = 31; 61 eyes). Among MS eyes, 87 had a history of ON before enrollment. The SD-OCT images were captured using Macular Cube (200×200 or 512×128) and ONH Cube 200×200 protocols. Retinal layer segmentation was performed using algorithms established for glaucoma studies. Thicknesses of the ganglion cell layer/inner plexiform layer (GCL+IPL), RNFL, outer plexiform/inner nuclear layers (OPL+INL), and outer nuclear/photoreceptor layers (ONL+PRL) were measured and compared in MS versus control eyes and MS ON versus non-ON eyes. The relation between changes in macular thickness and visual disability was also examined. The OCT measurements of GCL+IPL and RNFL thickness; high contrast visual acuity (VA); low-contrast letter acuity (LCLA) at 2.5% and 1.25% contrast; on the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and 10-Item Neuro-Ophthalmic Supplement composite score. Macular RNFL and GCL+IPL were significantly decreased in MS versus control eyes (P<0.001 and P = 0.001) and in MS ON versus non-ON eyes (P<0.001 for both measures). Peripapillary RNFL, macular RNFL, GCL+IPL, and the combination of macular RNFL+GCL+IPL were significantly correlated with VA (P≤0.001), 2.5% LCLA (P<0.001), and 1.25% LCLA (P≤0.001). Among OCT measurements, reductions in GCL+IPL (P<0.001), macular RNFL (P = 0.006), and the combination (macular RNFL+GCL+IPL; P<0.001) were most strongly associated with lower (worse) NEI-VFQ-25 and 10-Item Supplement QOL scores; GCL+IPL thinning was significant even accounting for macular RNFL thickness (P = 0.03 for GCL+IPL, P = 0.39 for macular RNFL). We demonstrated that GCL+IPL thinning is most significantly correlated with both visual function and vision-specific QOL in MS, and may serve as a useful structural marker of disease. Our findings parallel those of magnetic resonance imaging studies that show gray matter disease is a marker of neurologic disability in MS. Proprietary or commercial disclosure may be found after the references.

Diffusion Tensor Imaging Correlates of Visual Impairment in Multiple Sclerosis and Chronic Optic Neuritis

To compare white matter (WM) injuries associated with vision loss in multiple sclerosis (MS) and optic neuritis (ON). Twenty-three patients with clinically definite relapsing-remitting MS and chronic unilateral ON and 14 neurologically healthy volunteers were monocularly tested with Sloan 100%, 2.5%, and 1.25% contrast visual acuity charts. Primary visual pathway and whole-brain WM injury were assessed with optical coherence tomography (OCT) and diffusion tensor imaging (DTI). OCT and DTI correlates of high- and low-contrast visual impairment were identified using correlation analyses. The MS patients displayed significantly reduced retinal nerve fiber layer (RNFL) thickness and altered optic nerve and radiation DTI measures compared with the controls. In the patients, 2.5% and 1.25% contrast letter acuity in the unaffected eye correlated significantly and independently with optic nerve and optic radiation DTI measures. Visual acuity in affected eyes did not correlate with optic nerve or optic radiation DTI measures, but did correlate with DTI measures in prefrontal and temporal brain regions that were shown to connect structurally to visual cortices. In unaffected eyes, visual impairment was associated with WM injury in the visual pathway. In contrast, irrecoverable visual impairment after ON was associated with injury to frontal WM, which potentially impairs the capacity for remapping visual processing.

Ipsilateral Uveitis and Optic Neuritis in Multiple Sclerosis

Background. Uveitis is 20 times more frequent in multiple sclerosis (MS) patients than in the general population. Methods. A retrospective study of local multiple sclerosis (n = 700) and uveitis cohorts (n = 450) described the ophthalmological and neurological characteristics of patients with multiple sclerosis and uveitis. Results. Uveitis and multiple sclerosis were associated in seven patients. The time intervals between diagnoses of MS and uveitis ranged from 6 months to 15 years. Analysis of the patients' characteristics revealed that multiple sclerosis was associated with an older age of onset than usually expected, that is, 39 years. Uveitis was bilateral in three cases and mainly posterior (5/10). Five patients presented with acute optic neuritis (two in one eye and three in both eyes). All eyes presenting with acute optic neuritis were also affected by uveitis (P = 0.02), though not simultaneously. Conclusion. The ipsilateral association between optic neuritis and uveitis in this series of patients with multiple sclerosis may suggest a reciprocal potentiation between optic neuritis and uveitis in multiple sclerosis.

Early Diagnosis, Monitoring, and Treatment of Optic Neuritis

About half of multiple sclerosis patients present with optic neuritis (ON) as a clinically isolated syndrome (CIS). In the Optic Neuritis Treatment Trial study, 28% of patients with ON and an abnormal brain magnetic resonance imaging (MRI) did not have a relapse at the end of 15 years. It is still difficult to predict which CIS patients will go on to develop clinically definite multiple sclerosis and which will have a benign course. This review focuses on more advanced methods of detecting and quantifying ON in multiple sclerosis that have been developed in the past 15 years, especially on recent developments in optical coherence tomography measurement of the retinal nerve fiber layer and its role in monitoring axonal loss in the course of the disease. New clinical trial methods of measuring visual acuity include high-contrast visual acuity testing with the Early Treatment Diabetic Retinopathy Study charts, low-contrast letter acuity, and contrast sensitivity testing. More advanced neuroimaging techniques include magnetization transfer imaging and diffusion tensor imaging to quantify visual pathway lesions. Other tests of visual function, such as multifocal visual-evoked potentials and functional MRI, have been shown to be more sensitive than conventional visual-evoked potentials or MRI in detecting early, subtle visual impairment in ON and early recovery of visual function related to cortical plasticity. Newer agents are currently being investigated for CIS in ongoing clinical trials. Better methods are being developed for the earlier diagnosis, monitoring, and treatment of ON. In the future, CIS patients may be stratified according to their risk of development of clinically definite multiple sclerosis and therefore, receive the appropriate treatment.

The protective effects of erythropoietin/erythropoietin receptor system on optic nerve and retinal diseases

Erythropoietin(EPO) has an anti-apoptotic effect,and promotes the proliferation and differentiation of erythroid progenitor cells. Several studies have indicated that EPO can protect photoreceptor cells from the lightinduced retinal degeneration ;protect retinal neurons from ischemia-reperfusion injury and retinal ganglion cells after acute and chronic ocular hypertension; promote ganglion cell survival and axonal regeneration after optic nerve transaction; attenuate inflammation in multiple sclerosis optic neuritis; reduce the permeability of the retinal barrier and protect retinal neurons in diabetic retinopathy; enhance the stability of hypoxic retinal vessels in retinopathy of prematurity. Herein,we review the distribution of EPO and its receptor in retina,their expression in animal model of retinal diseases,and their effects and mechanisms in protection of retinal neurons and optic nerve. Key words: Erythropoietin; Erythropoietin receptor; Optic nerve; Retina; Neuroprotection

Bilateral and recurrent optic neuritis in multiple sclerosis

To assess the frequency of bilateral and recurrent optic neuritis (ON) in multiple sclerosis (MS) and to compare these results with epidemiological data of ON in neuromyelitis optica (NMO) and recurrent ON without other signs of disease. We identified 472 patients with diagnosis of MS from the Swedish Multiple Sclerosis Register. These patients were evaluated for the presence of ON and whether the ON was the presenting symptom of MS; unilateral or bilateral; monophasic or recurrent. Twenty-one percent presented with ON as their first manifestation of MS. The proportion of patients developing a second attack of ON before demonstration of other manifestations of MS was 5.5% and the frequency of recurrent bilateral ON as the presenting symptom was 3.8%. Only two patients presented with simultaneously appearing bilateral ON corresponding to 0.42%. Recurrent ON, whether unilateral or bilateral, is a common presentation of MS. As MS is a much more common disease than NMO, care must be taken when evaluating the work-up of patients with recurrent ON. In some cases repeated MRI and lumbar punctures are warranted to improve diagnostic accuracy, even in the presence of the serological marker NMO-IgG.

Nerve Fiber Layer and Macular Thinning Measured with Different Imaging Methods during the Course of Acute Optic Neuritis

To compare retinal nerve fiber layer thickness (RNFLT) and inner macula thickness changes measured with Fourier-domain optical coherence tomography (FD-OCT) and scanning laser polarimetry during the course of acute optic neuritis (ON). Nine eyes of 7 consecutive patients with multiple sclerosis (MS) were prospectively imaged from the onset of ON for 6 to 12 months. Nine healthy eyes were imaged for 12 to 19 months. Retinal nerve fiber layer thickness measured with FD-OCT initially increased in all eyes with diffuse optic disc edema. Inner macula thickness and polarimetric RNFLT decreased already in the acute phase, in all eyes. All parameters stabilized at 2 to 5 months. The relative structural loss was different with the different methods. Poor image quality with polarimetry occurred in 2 eyes in the acute phase of ON. In the control eyes all parameters were stable. Change of RNFLT and macular thickness during the course of acute ON in MS strongly depends on the method used for the measurement. Inner macula thickness, measured with FD-OCT, was especially useful for the follow-up, since it was not influenced by initial disc edema and had consistently high image quality.

Recurrent optic neuritis: clues from a long-term follow up study of recurrent and bilateral optic neuritis patients.

Optic neuritis (ON) can be recurrent, with unilateral or bilateral presentation. Diagnosis of recurrent cases may be challenging. In this study long-term follow-up of recurrent and/or bilateral ON patients is reported in an effort to guide differential diagnosis and treatment. The study included 474 optic neuropathy patients. Of these, 70 patients with recurrent unilateral or bilateral, and nonrecurrent bilateral ON were assessed. The characteristics of each ON attack, laboratory and magnetic resonance imaging (MRI) findings, associated diseases and response to treatment were noted for each patient. Most of the patients were reevaluated in the outpatient clinic. Seven patients were investigated for neuromyelitis optica (NMO)-immunoglobulin G (IgG) seropositivity. Forty-seven patients had recurrent unilateral ON and 23 had bilateral ON. Mean follow-up was 7.55 years. Final diagnoses for recurrent unilateral group were multiple sclerosis (MS) (n = 29), chronic relapsing inflammatory optic neuritis (CRION) (n = 11), NMO (n = 4), or autoimmune thyroid disease (n = 3); and for bilateral ON group, MS (n = 4), vasculitis (n = 13), postinfectious ON (n = 4), and sarcoidosis (n = 2). Three patients were positive for NMO antibodies. Based on the data collected, we conclude when recurrent ON causes moderate to severe visual loss in the absence of cranial MRI findings typical of MS, other diagnoses should be considered, including NMO.

Increased immunopotency of monocyte derived dendritic cells from patients with optic neuritis is inhibited in vitro by simvastatin

Multiple sclerosis (MS) is an autoimmune disease where myelin-reactive lymphocytes and their activation depend on interactions with antigen presenting cells (APCs). Dendritic cells (DC) are professional APCs dependent on maturation to attain full T-cell priming capacity. The immunomodulatory properties of simvastatin influence the function of both T cells and APCs and could thus be a potential therapy for MS. The phenotype of myeloid DC in untreated patients with monosymptomatic optic neuritis (ON) was determined by flow cytometry and the impact of simvastatin on the function of myeloid DC derived from peripheral blood mononuclear cells (PBMC) was analysed in vitro. DC from ON patients had more mature phenotype compared with healthy controls (HC). Particularly the fraction of DC expressing CD1a and CD80 was significantly higher in ON than in HC ( P < 0.05). Addition of 10 μΜ simvastatin significantly inhibited the maturation of DC in the ON group. Furthermore, ON derived DC induced stronger T-cell proliferation in the mixed leukocyte reaction (MLR), and simvastatin solely inhibited this proliferation of T-cells in the ON group and not in HC. In conclusion DC from ON patients have a more mature phenotype and an increased stimulatory capacity. Simvastatin has an inhibitory effect on the differentiation and maturation of DC, and selectively reduce the T-cell proliferation induced by DC from patients with ON. The results from these in vitro assays suggest potential beneficial inhibitory effects of Simvastatin in the inflammation in ON and early MS, but we need more clinical trials to confirm it.

This issue of Acta

The cover illustrations are contributed by Gysbert van Setten and show the bimanual insertion of a capsular tension ring as reported in this issue of Acta. Anders Behndig discusses the pros and cons of operating both eyes for cataract at the same time and discusses the article by Lundström et al. in this issue. Resch and associates in Vienna review the evidence for endothelial dysfunction in glaucoma and its relevance in the ischemic nature of glaucoma. Kawasaki and Purvin in Switzerland and USA present a comprehensive review of giant cell arteritis including epidemiology, pathophysiology and treatment. Lundström et al. in Sweden point out that it is less expensive to operate both eyes of a cataract patient in the same setting. The pros and cons of this approach are discussed further in the editorial by Behndig. Karalezli et al. in Turkey find changes in conjunctival impression cytology and the tear film in patients with Mediterranean fever. Kimura et al. en Japan did not find adenovirus before the onset of symptoms in adenoviral conjunctivitis. Wollensak and Iomdina in Germany and Russia found that photodynamic collagen cross-linking increases the rigidity of the rabbit cornea. Berker et al. in Turkey examined the genetic pattern of Peters' anomaly. Bordaberry et al. in Brazil found peribulbar injection of trimacinolone to reduce inflammation in Graves' ophthalmopathy and optic neuropathy. Hradilek et al. in the Check Republic describe transient changes in orbital hemodynamics in optic neuritis in multiple sclerosis. Konstas et al. in Greece and United States found that a fixed combination of travoprost and timolol reduces intraocular pressure over a 24-hour period. Rensch et al. in Germany found that intravitreal bevacizumab improves vision and reduces macular edema in non-ischemic central retinal vein occlusion. Sharma et al. in United States suggest that preconditioning may protect retinal pigment epithelial cells from oxidative stress in an in vitro experiment. Schmid-Kubista in Vienna found that patients with age-related macular degeneration produce less melatonin than control patients without macular degeneration. Saricaoglu et al. in Turkey describe decompression retinopathy following glaucoma filtering surgery. Abouzeid et al. in Switzerland and Germany used optical coherence tomography to show that subretinal fluid may persist for months after scleral buckling surgery inferior detachments. Song et al. in Korea used intravitreal bevacizumab to treat choroidal neovascularization with a choroidal osteoma. Ikewaki et al. in Japan describe a fungal abscess following triamcinolone injection. I hope that the readers of Acta find sources of enjoyment and education in this issue of Acta. I wish you all a Happy New Year.

Colour Doppler imaging evaluation of blood flow parameters in the ophthalmic artery in acute and chronic phases of optic neuritis in multiple sclerosis

Optic neuritis (ON) is a common manifestation of multiple sclerosis (MS). It is caused by the immune-mediated inflammation of the optic nerve. Some vascular factors that may influence blood flow in the ophthalmic artery (OA) have also been suggested as factors in the pathogenesis of ON. The purpose of our study was to evaluate blood flow velocities and resistance (RI) and pulsatile (PI) indices in the OA in both orbits in patients in the acute and chronic phases of unilateral ON and to compare these with equivalent findings in healthy control subjects. Orbital colour Doppler imaging (CDI) was performed in 40 consecutive MS patients during acute unilateral ON prior to corticosteroid treatment. Optic neuritis was diagnosed on the basis of clinical presentation and facultative assessment of visual evoked potentials (VEPs). The peak systolic (PSV) and end-diastolic (EDV) velocities and RI and PI were measured in the OA in both eyes. We compared results from affected and unaffected orbits using the paired t-test. The same measurements were performed in 114 MS patients with a history of acute unilateral ON that occurred > 1 year prior to ultrasound examination. We also measured the same parameters in the middle cerebral arteries (MCAs) on both sides in all subjects in both groups. The same measurements were obtained in healthy controls. The PSV (p < 0.0001), RI (p < 0.0001) and PI (p < 0.0001) in the OA in the eye affected with acute ON were significantly higher than in the unaffected eye. There was no difference in EDV in the OA between affected and unaffected eyes (p > 0.05) in the group with acute ON. We did not observe any significant differences between eyes in either blood flow velocities or the RI or PI (p > 0.05) in the group in the chronic phase of ON or in the control group. All the parameters in the MCAs on both sides were normal in both the acute and chronic groups, as well as in the control group. Pathophysiological changes during acute unilateral ON influence orbital haemodynamics, as is indicated by increased PSV, RI and PI in the OA in eyes affected with ON. However, these changes do not persist over longer periods.

Loss of contrast sensitivity in multiple sclerosis patients

Neuro-ophthalmicim pairments are commonin multiple sclerosis (MS). Previous reports have shown that contrast sensitivity (CS) may be the most sensitive measure of afferent visual disfunction in patients with MS, even while sparing visual acuity. OBJECTIVE: To investigate CS testing as a method for detection of visual disturbances in MS patients with or without clinical data of retrobulbar neuritis. MATERIALS AND METHODS: CS was measured in 24 patients divided into two groups as follows: 12 cases with clinical data of retrobulbar neuritis (ON+) and 12 without medical history of retrobulbar neuritis (ON-). RESULTS AND CONCLUSION: CS was abnormal in 91, 7 % of the patients from the first group and in 83,3 % of the patients from the second group. Visuograms of mean CS's as a function of the spatial frequency in 30 normal subjects, 12 MS ON+ patients and 12 MS ON- patients. No statistically significant variations were established between the both investigated groups of MS patients. Our study confirms the previously reported abnormalities in CS curve in patients with normal and reduced visual acuity. This report proves the possibility of this test to benefit the earlier diagnosis of Multiple Sclerosis and to improve the detection of latent visual deficit. Scripta Scientifica Medica 2008;40(1):75-77

Optical coherence tomography and disease subtype in multiple sclerosis

To examine retinal nerve fiber layer (RNFL) thickness, macular volumes (MV), and visual acuity in multiple sclerosis (MS) eyes, with and without history of acute optic neuritis (ON). RNFL thickness was measured in 326 MS and 94 control eyes using optical coherence tomography (OCT). MV and vision testing were done in a subset of the cohort. MS subtype was classified as relapsing-remitting (RRMS, n = 135), primary progressive (PPMS, n = 12), and secondary progressive (SPMS, n = 16). MS ON eyes had decreased RNFL thickness (84.2 microm) compared to controls (102.7 microm) (p < 0.0001). Unaffected fellow eyes of MS ON eyes (93.9 microm) (p < 0.01) and patients with MS with no history of ON (95.9 microm) (p < 0.05) also had decreased RNFL. RRMS (94.4 microm) (p < 0.001), PPMS (88.9 microm) (p < 0.01), and SPMS (81.8 microm) (p < 0.0001) (adjusted for age and duration of disease) had decreased RNFL compared to controls. There were significant differences in RNFL thickness within quadrants of peripapillary retina comparing relapsing to progressive MS subtypes. MV was decreased in MS ON eyes (6.2 mm(3)) (p < 0.0001) and SPMS subjects (6.2 mm(3)) (p < 0.05) compared to controls (6.8 mm(3)). Retinal nerve fiber layer (RNFL) is significantly decreased in multiple sclerosis (MS) optic neuritis (ON) eyes, unaffected fellow eyes of patients with MS ON, and MS eyes not affected by ON in our cohort. Macular volumes (MV) showed a significant decrease in MS ON eyes. Progressive MS cases showed more marked decreases in RNFL and MV than relapsing-remitting MS. OCT is a promising tool to detect subclinical changes in RNFL and MV in patients with MS and should be examined in longitudinal studies as a potential biomarker of retinal pathology in MS.

Autoantibodies to the proteasome in monosymptomatic optic neuritis may predict progression to multiple sclerosis

Objective. Proteasome autoantibodies (PAB) have been found in multiple sclerosis (MS) patient sera and cerebrospinal fluid (CSF). Presence of PAB could thus be a possible diagnostic marker for MS. We investigated whether PAB serum status in acute monosymptomatic optic neuritis (ON) and MS differed significantly from that of healthy controls, and whether or not PAB status is predictive of later MS development in patients with ON. Material and methods. Sera from ON patients, MS patients and healthy donors were analysed retrospectively using ELISA. Subsequently, a small group of PAB‐positive samples were subjected to SDS‐PAGE, immunoblotting and 2‐D PAGE. Results. We found that 20 % (6/30) ON patients, 47 % (22/47) MS patients and 9 % (7/81) controls tested PAB positive using ELISA analysis. High PAB levels were found in 2 (4 %) MS patients, 1 (3 %) ON patient and 2 (3 %) controls. PAB positivity in ELISA was confirmed by immunoblotting. Separation of proteasome subunits by 2D PAGE followed by immunoblotting revealed no particular PAB subunit preference. Conclusions. A retrospective search in available patient files revealed that 6 of 6 (100.0 %) PAB‐positive ON patients developed MS over time. Eight of 24 (33 %) PAB‐negative ON patients developed MS over time and 47 % (14/30) of all ON patients developed MS. A series of patient CSF was analysed by ELISA to assess the possible correlation between PAB status of concurrent serum and CSF samples, but no correlation was found. However, the results from the six PAB‐positive ON patients could potentially be of prognostic value.

Relation of Visual Function to Retinal Nerve Fiber Layer Thickness in Multiple Sclerosis

To examine the relation of visual function to retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in multiple sclerosis (MS), and to compare RNFL thickness among MS eyes with a history of acute optic neuritis (MS ON eyes), MS eyes without an optic neuritis history (MS non-ON eyes), and disease-free control eyes. Cross-sectional study. Patients with MS (n = 90; 180 eyes) and disease-free controls (n = 36; 72 eyes). Retinal never fiber layer thickness was measured using optical coherence tomography (OCT; fast RNFL thickness software protocol). Vision testing was performed for each eye and binocularly before OCT scanning using measures previously shown to capture dysfunction in MS patients: (1) low-contrast letter acuity (Sloan charts, 2.5% and 1.25% contrast levels at 2 m) and (2) contrast sensitivity (Pelli-Robson chart at 1 m). Visual acuity (retroilluminated Early Treatment Diabetic Retinopathy charts at 3.2 m) was also measured, and protocol refractions were performed. Retinal nerve fiber layer thickness measured by OCT, and visual function test results. Although median Snellen acuity equivalents were better than 20/20 in both groups, RNFL thickness was reduced significantly among eyes of MS patients (92 mum) versus controls (105 mum) (P<0.001) and particularly was reduced in MS ON eyes (85 mum; P<0.001; accounting for age and adjusting for within-patient intereye correlations). Lower visual function scores were associated with reduced average overall RNFL thickness in MS eyes; for every 1-line decrease in low-contrast letter acuity or contrast sensitivity score, the mean RNFL thickness decreased by 4 mum. Scores for low-contrast letter acuity and contrast sensitivity correlate well with RNFL thickness as a structural biomarker, supporting validity for these visual function tests as secondary clinical outcome measures for MS trials. These results also suggest a role for ocular imaging techniques such as OCT in trials that examine neuroprotective and other disease-modifying therapies. Although eyes with a history of acute optic neuritis demonstrate the greatest reductions in RNFL thickness, MS non-ON eyes have less RNFL thickness than controls, suggesting the occurrence of chronic axonal loss separate from acute attacks in MS patients.

Acute Optic Neuritis in Multiple Sclerosis: Evaluation of Hemodynamics in the Ophthalmic Artery with Colour Doppler Imaging

Background: Optic neuritis (ON) is a common manifestation of multiple sclerosis. It occurs because of the immune-mediated inflammation of the optic nerve. Some vascular factors that could influence the blood flow in the ophthalmic artery (OA) have been suggested in the pathogenesis of ON as well. The purpose of our study was to evaluate blood flow velocities and resistance (RI) and pulsatile (PI) indexes in the OA in patients with acute unilateral ON. Materials and methods: Orbital color Doppler imaging was performed in 27 consecutive patients during acute unilateral ON prior to corticosteroid treatment. ON was diagnosed on the basis of clinical presentation, acute unilateral loss of vision, and assessment of visual evoked potentials (VEP). The peak-systolic velocity (PSV) and the end-diastolic velocity (EDV) and RI and PI were measured in the OA on both sides. We compared results from affected and unaffected orbits, using the paired t-test. We also measured the same parameters in the middle cerebral arteries (MCA) on both sides. Results: The PSV (p < 0.0001), RI (p < 0.0001), and PI (p < 0.0001) in the OA on the side affected by acute ON were significantly higher compared to the unaffected side. There was no difference in EDV in the OA between affected and unaffected sides (p > 0.05). All the parameters in the MCA on both sides were normal. Conclusion: Pathophysiological changes during acute unilateral ON influence the orbital hemodynamics as documented by increased PSV, RI, and PI in the OA on the side affected by ON.

Optic neuritis in multiple sclerosis

Purpose: To review the clinical features, natural history, potential pathogenic mechanisms, differential diagnosis, and management of optic neuritis in multiple sclerosis. Methods: Relevant literature regarding optic neuritis in multiple sclerosis from 1970 to the present was reviewed. Results: Optic neuritis is an acute inflammatory optic neuropathy. It is the most common type of optic neuropathy causing acute visual loss in young adults (peak age at 30-40 years), especially among women. Patients usually present with an acute reduction of visual acuity, orbital pain exacerbated by eye movements, dyschromatopsia, and an afferent papillary defect, with or without swelling of the optic nerve head. Visual field testing most often reveals central defects, but others, such as centrocecal, can also occur. Magnetic resonance image (MRI) scanning of the brain should be undertaken in all cases of acute optic neuritis for diagnostic and prognostic purposes. The brain lesions of multiple sclerosis are commonly seen as T2 ovoid high-signal white matter lesions on MRI scans of the brain located in perivenular regions perpendicular to ventricles with variable enhancement. For atypical presentations of optic neuritis, additional laboratory tests, such as cerebrospinal fluid analysis, serologic tests, and visual evoked potentials, prove to be useful in the diagnosis and subsequent management of the patient. The recommended treatment for optic neuritis is intravenous steroids, as shown in the Optic Neuritis Treatment Trial (ONTT). Conclusion: Optic neuritis is often the initial presentation of multiple sclerosis. Recent advances in the understanding of the immune basis for multiple sclerosis has led to earlier and more effective treatment of this disease.

Optic neuritis in chronic relapsing experimental allergic encephalomyelitis in Biozzi ABH mice: Demyelination and fast axonal transport changes in disease

The encephalitogenicity of optic nerve tissue was demonstrated in Biozzi ABH (H-2 dq1) mice. Acute experimental allergic encephalomyelitis (EAE) occurred in 11/14 animals and 4/5 exhibited relapse. The involvement of the optic nerve in spinal cord homogenate induced chronic relapsing EAE (CREAE) was demonstrated by mononuclear cell infiltration and myelin degradation in the optic nerve prior to and during clinical disease. During the relapse phase gross pathological assessment revealed swollen and translucent plaques on the optic nerves. Advanced lesions showed widespread demyelination, astrocytic gliosis and fibrotic changes of the blood vessels. Physiologically, the fast axonal transport of proteins from the retina to the optic nerve and superior colliculus was significantly decreased during relapse. The association of inflammation and demyelination with physiological deficit in the optic nerve highlights the usefulness of this model in the study of multiple sclerosis in which acute monosymptomatic unilateral optic neuritis is a common manifestation. Furthermore, the novel induction of CREAE with optic nerve homogenate suggests that optic nerve antigens play a significant role in the pathophysiology and progression of neurological disease in CREAE which may be relevant to studies of optic neuritis in multiple sclerosis.

Neurophysiological and CSF immunological study of 19 patients affected by acute idiopatic optic neuritis.

We studied 19 patients affected by acute idiopatic optic neuritis (ON), with neurophysiological tests: visual (VEP), somatosensory (SSEP), acoustic (ABR) evoked potentials and study of the blink reflex (BR), and with cerebrospinal fluid (CSF) examination, in order to detect "silent" lesions in the central nervous system (CNS) and/or immunological alterations, suggestive of multiple sclerosis (MS). The percentage of cases with at least one altered CSF IgG parameter (IgG index, IgG synthesis/day and IgG oligoclonal bands) has been higher than that of cases with one or more altered neurophysiological tests, regardless of the apparently intact eye VEP. If we also included this last test, the 2 percentages become identical. The validity of these tests in predicting the evolution of ON in MS is discussed.